Method for reclaiming silk



July 3, 1934.

l. DAVIS 1,965,455

METHOD FOR RECLAIMING SILK Filed 0012.8, 1952 Sheets-Shet 1 INVENTQRWITNESSES \a an Isaac- Haul/5 S4,? BY

W ATTORNEYJ July 3, 1934.

Filed Oct. 8, 1952 ITNESSES 2 Sheets-Sheet 2 INVENTOR Lsaac ,Z7avi5ATTORNEYS Patented July 3, 1934 UNITED STATES PATENT OFFICE 7 Claims.

The invention relates to the recovery of .silk threads from old, wornsilk hose or other silk garments and it has for an object the treatmentof the silk threads to rejuvenate them so that they will have all thebody strength and resiliency of new silk. The invention also relates tothe treatment of old and "new silk threads to make the silk threadscurly, kinky and flufiy.

An object of the invention is to provide an inexpensive method ofreclaiming silk threads and yarns from old silk hose, old silk neckwearand factory knitwear waste.

Another object of the invention is to provide a method of treating oldor new silk threads and yarns which will make the silk threads and yarnscurly, kinky and fluffy and will increase their resiliency, the curly,kinky and fluffy character of the silk threads and yarns, as well astheir resiliency, being maintained when the silk threads and yarns havebeen manufactured into cloth of various kinds, such as plain weaves,crepe silk, jacquard weaves, knitted weaves and diagonal or fancyweaves, pile fabrics, plushes, silk rugs, upholstery coverings, hangingsand table covers, as well as knitted wearing apparel. Garments madeeither from the new or reclaimed treated silk will have the desiredresiliency, as well as the curly, kinky and fiufiy properties, and thegarments will not sag, bag, crease or cling to the body of the wearerand will resiliently give to the movements of the body of the wearer.The silk product may be made with a lustre, or may be made lustreless,as desired.

Another object of the invention is to provide a method of treatingreclaimed silk in which the silk is free from weighting or foreignmatter, the reclaimed silk being such that it will not be affected byperspiration.

Still another object of the invention is to provide a silk which is easyto dye because of its fiufiiness, as the fiufiy silk absorbs the dyereadily. Still another object of the invention is to provide a reclaimedsilk which has a long staple quality and which is not madefromspunshoddy silkof short staples.

The invention also comprehends a method. of treating silk threads or.yarns in which the yardage perpound for the sainegauge denier thicknessis increased. When the treated-silk is used as a filler, it'gives thebest results, as the filler gives the desired resiliency.

The invention further comprehends a method of carbonizing vegetablematter from the old silk which is to be, reclaimed and which leaves thesilk undamaged.

The invention still further comprehends a method of treating an old silkfabric or garment which permits the rapid and convenient unraveling ofthe silk thread from the fabric or garment.

The invention also has for an object to provide a method of treating oldsilk thread or yarnto replace the matter which has been lost in the useof the silk fabric or garment and by washin and ironing.

In addition, the invention comprehends an 3P.- paratus for use inconnection with the method.

Additional objects of the invention will appear in the followingspecification in. which the preferred form of the invention isdescribed.

In the drawings similar reference characters refer to similar parts inthe several views, of

which Figure 1 is a view showing the apparatus used in carbonizingvegetable matter from the old silk fabric or garment,

Figure 2 is a schematic view illustrating the apparatus for and themanner of unraveling, the thread from the fabric, together with the twotanks, in one of which there is boiling water, to remove the paraffinfrom the thread which, has been sprayed on the fabricor garment, thesece ond tank being providedv for reconditioning the silk thread, theview also showing. the eyelet through which the silk thread passesfromxthe second mentioned tank, and. 1 f

Figure 3 is a view illustrating the two tanks, one for heating the silkthread and the second tank for cooling the silk thread, and showing themeans for transferring the silk thread from the first tank to the secondtank.

In carrying out the method which is the suba ject matter of thisapplication, old discarded silk hose or other silk garments or fabrics,as well as new discarded knittedsilk factorywaste, obtained and sortedwith reference to color and all rayon and cotton portions, as well asforeign matter, are removed by scissors or a rotary knife and, if silkthread or yarn portions of the silk hose or othe'rsilk garmentslor.fabrics'ds pfa coarser grade than the leg. orbody portion, such as thetop, this is removedand sorted separately with reference to colorf. Thecottonito'ps of e silkhose areflaid'aside as? produc and the same may be'rewound into cotton suitable for warp for. rag rugs or coarse cloth,fThe poriQ-L tions which are cut from thefeetof thje'silk'hose, andwhich consist mostlyofsilk and bleached and madev into afine shoddy."

In the manufacture of full-fashionedisil he the edges of the hose arecustomarilysewed as i io s

y no

' garments or fabrics.

gether with cotton. This cotton is removed by carbonizing in thefollowing manner:-

A chamber 5 is provided having a stack 6, the chamber 5 being air-tightand the stack 6 being provided with a damper '7 which is pivoted inthestack 6 and is operable by a handle 8. In the chamber 5 there isdisposed a drum 9 having openings therethrough and provided with anopening closed by a door 10, it being possible to dispose the old silkhose or other silk garments or fabrics in the drum 9 through the saidopening closed by the door. The drum is mounted for rotating on bearings11 and has a shaft 12 with a pulley 13 which is connected by a belt 14with a motor 15, this means being provided for rotating the drum 9 inthe chamber 5. Adjacent the chamber 5 there is a receptacle 16 with ahinged cover 17 which is held in closed position by a bolt and wing nut18, the receptacle 16 being provided for receiving muriatic acid whichis heated in the receptacle 16 by an electrical or other heater 19, thereceptacle 16 having an outlet 20 which is connected with an inlet 21 inthe chamber 5 by means of a conduit 22 in which there is a blower 23.

The silk hose or other silk garments or fabrics are moistened by steamand they are then disposed in the drum 9. The drum 9 is preferably ofsuch a size as to receive approximately five hundred pounds of the silkhose or other silk garments or fabrics. The door 10 of the drum 9 isthen closed, a door 24 in the chamber 5 is also closed and the damper 7is closed. The drum is rotated for approximately thirty minutes andsubjected during this time to the action of the gases or fumes from themuriatic acid, which have been generated in the receptacle 16, aretransmitted by the blower 23 to the chamber 5. At the end of this periodthe rotation of the drum 9 is discontinued, the operation of the blower23 also being discontinued, and the damper '7 in the stack 6 is opened.After a reasonable time, which may be fifteen minutes, the door 24 forthe chamber 5 is opened and the silk hose or other silk garments orfabrics in the drum 9 are removed. The treatmentof the silk hose orother silk garments or fabrics with the hot muriatic acid gas fumescarbonizes the cotton and other vegetable matter which may have beenused in the manufacture of the silk hose or other silk garments orfabrics without in any way damaging the silk hose or other silk In thisoperation it is important that the operator use a gas mask.

When the silk hose or other silk garments or fabrics have been removedfrom the drum 9 they are placed in a well-heated drying room in order todry up the carbonized vegetable matter, after which this carbonizedvegetable matter may be shaken as dust from the silk hose or other silkgarments or fabrics. With this operation all the cotton and vegetablematter is removed.

With the cotton seam removed from the fullfashioned silk hose and thecotton and other vegetable matter removed from the silk hose or othersilk garments or fabrics, the silk is decolorized and bleached. In thisoperation from one hundred and fifty to two hundred gallons of freshwater, free from salts or alkali, are used fo each one hundred pounds ofunseamed silk hose or other silk garments or fabrics, and approximatelyfour or five pounds of sodium hydrosulphite in powdered form are used toeach one hundred pounds of the unseamed silk hose or other silk garmentsor fabrics, and this sodium hydrosulphite in powdered form is mixed withwater in a separate vessel. When the same isdissolved, the solution ispoured into a tank or vat with the one hundred and fifty to two hundredgallons of fresh water. One pound of liquid sulphuric acid is dilutedwith water in a separate vessel, which is used for 'each one hundredpoundsof the unseamed silk hose or other silk garments or fabrics. Thisdiluted sulphuric acid is then poured into the tank or vat containingthe water and sodium hydrosulphite solution and the contents of the tankor vat are thoroughly mixed. This solution is then brought to a boilingpoint by steam, or by other means. Wire baskets containing the unseamedsilk hose or other silk garments or fabrics are lowered into the tank orvat and the unseamed silk hose or other silk garments or fabrics arethoroughly stirred into the solution so that the solution will beabsorbed by every part of the unseamed silk hose or other silk garmentsor fabrics. When the unseamed silk hose or other silk garments orfabrics indicate that the colors have been entirely stripped therefrom,the wire baskets are removed from the tank or vat and the solution ispermitted to drain from the unseamed silk hose or other silk garments orfabrics. The silk hose or other sik garments or fabrics are then treatedin a bath to neutralize the bleaching compound in the customary manner.

After the stripping of the colors has been completed inthe manner setforth, the unseamed silk hose or other silk garments or fabrics arewashed to remove oil, grease, ointments or paints that the carbonizingand stripping operations may have failed to remove. In this step of themethod five pounds of silkworm-oil soap or greenolive-oil soap are usedin hot water and this washing operation may consume approximately thirtyminutes. The unseamed silk hose or other silk garments or fabrics arethoroughly agitated and stirred during the washing. While it isadvisable to use silkworm-oil soap, or greenolive-oil soap, in somecases palm-olive-oil soap heads may 'be employed. After this washing.

process has been carried on for approximately thirty minutes, theunseamed silk hose or other silk garments or fabrics are rinsed in freshwater to free the soap therefrom, whenthe water is drained from theunseamed silk hose or other silk garments or fabrics and they aresubsequently dried, preferably in the sun. After the unseamed silk hoseor other silk garments or fabrics have been thoroughly dried, they aresorted as to colors and shades and those which have not been entirelystripped of their colors, on account of having been dyed with basiccolors, and any wild silk, are put aside and are dyed in logwood andiron black dye and unwound into black silk yarn.

After the unseamed silk hose or other silk garments or fabrics have beensorted as has been described, the ends of each of the silk threads oryarns are drawn out and are graded. This may be done by strongmagnifying lenses, by weighing a portion of each thread or yarn, or byother means. With the unseamed silk hose or other silk garments orfabrics not only sorted as to color, but also graded as to the denierthickness oftlie silk thread or yarn, the unseamed silk hose or othersilk garments or fabrics are treated prior to the unraveling orunwinding of the silk thread or-yarn therefrom. This is done by the useof white paraflin dissolved in carbon tetrachloride which makes a thinfluid, and this thin fluid is sprayed on the unseamed silk hose or othersilk garments or fabrics, which saves labor in unwinding the silk threador yarn. With the spraying of the parafiin, which is a waxy material, onthe unseamed silk hose or other silk garments or fabrics, the silkthread or yarn is coated therewith and this retains the loose filamentsof the silk thread-or yarn in place and prevents the silk thread or yarnin the unseamed silk hose or other silk garments or fabrics fromcatching, webbing, or becoming tangled during the unwinding operation.This is important, for the silk thread or yarn in the unseamed silk hoseor other silk garments or fabrics has become felted from the washing,ironing and use of the unseamed silk hose or other silk garments orfabrics.

After the unseamed silk hose or other silk garments or fabrics have beencoated with the parafiin or waxy material in the manner set forth, theunseamed silk hose or other silk garments or fabrics 25 are hung, asillustrated in Figure 2, by hooks 26 on a support 27 and the silk threador yarn 28 is drawn therefrom. The silk thread or yarn 28 is preferablydrawn from the bottom of the unseamed silk hose or other silk garmentsor fabrics and it is pulled through a porcelain tube 29 which isdisposed in a tank 30 containing hot water, theweight of the tube 29serving to draw, the silk thread or yarn under the hot water containedin the tank 30 and the hot water serving to release the paraflin. Thesilk thread or yarn 28 then passes over a roller 31 into a second tank32 and passes through another porcelain tube 33 in the said tank 32.This tank 32 contains a material which will rejuvenate the silk threadoryarn and replace the albumen, silicon and other matters which the silkthread or yarn has lost in wearing, washing and other ways.

I Secretions from dead silkworms, that is, the mummies, are obtained,after the raw silk has been unwound therefrom, by pressing the deadsilkworms or mummies. This secretion,'fiuid or oil obtained from themummy of the silk worm contains silicon, albumen and a certain amount ofcelesin.

The material contained in the tank 32 consists of seventy-five percentof the secretions from the dead silkworms, one percent of dilutedcarbolic acid, five percent of citric acid crystals dissolved informaldehyde mixed with water, and nineteen percent additionalformaldehyde mixed with water. The one percent of the carbolic acid ispoured on the-seventy-five percent of the secretions from the deadsilkworms to purify the same, after which the five percent of citricacid crystals dissolved in formaldehyde and, subsequently the nineteenpercent additional formaldehyde mixed with water, is added to themixture. The solution is mixed thoroughly and allowed to stand forapproximately three days in a cool place, after which it is ready foruse and is disposed in the tank 32 for the purpose set forth.

The silk thread or yarn 28, after passing through the porcelain tube 33in the tank 32, passes through a smooth eyelet 34 with a hole as fine asthe silk thread or yarn and, as the silk thread or yarn passes throughthe eyelet 34, the eyelet 34 serves to press the loose filaments against.the long staple yarn and the material from the tank 32, with which thesilk thread or yarn has become coated, is pressed into the silk threador yarn in very much the same manner that a shoemaker waxes thread. Thesilk thread or yarn 28 which has now been treated to replace the matterslost in the wearing and washing of the silk hose, or other'silk garmentsor fabrics, and which is rejuvenated, is wound on winding frames readyto be made into standard size hanks and is hung up for drying purposes.

This rejuvenated silk thread or yarn may, of course, be used in variousways and for various purposes. In the ordinary manufacture, a number ofthe silk threads or yarns are thrown together in the customary manner.For instance, where three plys or pieces of the silk threads or yarnsare thrown together, two silk threads or yarns are selected and each isthrown or twisted by any silk throwing machine five hundred and fiftytimes or turns, or more, to the left, when the other or third silkthread or yarn is thrown one hundred and seventy times or turns to theright, the three silk threads or yarns being then bunched together andthrown or twisted together one hundred and fifty times or turns to theright. ever, it will be understood that any number of these silk threadsor yarns may be thrown together in any desired manner.

After the silk threads or yarns have been thrown together in the mannerstated, and before the thrown silk threads or yarns have been made intohanks, the silk thread or yarn is passed through an albumen form ofdressing. Albumen, either from the white of egg or other organic albumenmatter, is used. The albumen is made into a very fine foam by passingthe same through a beating machine such as an egg beater used by bakers.The foaming albumen is then placed in a tank or vessel and so arrangedthat the silk thread or yarn passes through this foaming albumen. Thesilk thread or yarn takes on the albumen dressing, which assists inrebuilding the silk thread or yarn and adding to its strength. The silkthread or yarn is then made into standard size hanks:

When the hanks of silk thread or yarn have been dried, after beingcoated with the albumen dressing, these hanks of silk thread or yarn aredisposed in an open-work receptacle 35 which is supported by a cable 36,the cable passing over a pulley 37 on a carriage 38 which travels on arail 39. This receptacle 35 is lowered into a tank 40 containing water41 which is heated to the boiling point by passing steam through pipes42 and the hanks of silk thread or yarn, which are contained in thereceptacle 35, are lowered into the tank 40 containing the boilingwater, three percent of olive-oil soap cut fine having been added to thewater 41 in the tank 40. After the hanks of silk thread or yarncontained in the receptacle 35 have been disposed in the tank 40 for aperiod of thirty minutes, the receptacle 35 is drawn upwardly from thetank by means of the cable 36 and the carriage 38 is moved above a tank43 which is cooled by passing a refrigerant through these pipes 44. Thereceptacle 35 containing the hanks of silk thread or yarn is loweredinto the tank 43, the action of the cold water on the silk thread oryarn, which has been previously subjected to the boiling water in thetank 40, serving to shrink or shrivel the silk thread or yarn and thisgives the silk thread or yarn a curly, kinky and fiuify property. Thesilk thread or yarn is permitted to remain in the tank 43 for a periodof one hour.

The curly, kinky and fiufiy silk thread or yarn is then treated topreserve the shrinking and resiliency which has been acquired by thesilk thread or yarn in its previous treatment, the silk thread or yarnbeing disposed in a tank containing approximately two and one-half tothree pounds of granulated casein to each one hundred HOW- pounds ofsilk thread or yarn, the granulated casein having been dissolved withthe aid of liquid ammonia in a .separate vessel, after which luke warmwater is added. The dissolved casein is then poured through a fine wirestrainer into the tank, after which from one-half to one percent of purelactic acid is mixed with the other ingredients in the tank and thehanks of silk thread or yarn are disposed in this casein bath, in whichthey are permitted to remain for approximately fifteen minutes, afterwhich the hanks of silk thread or yarn are removed from the tank and thecasein solution is permitted to drain therefrom. The hanks of silkthread or yarn are then permitted to dry, preferably in the sun.

After the silk thread or yarn has been treated with the casein solutionand is partially dry, it is given another cold bath to which is addedfrom one percent to one and a half percent of formaldehyde in water,this bath being used for preserving purposes. The silk thread or yarn ispermitted to remain in this bath for twenty minutes, when the silkthread or yarn is removed from the bath. The fluid is removed from thesilk thread or yarn by a wringer or other means.

The last step in the method is "the immersion of the silk thread or yarnin a bath of cold water to which has been added approximately from eightto ten percent of formic acid. The silk thread or yarn is hung on polesand it is turned on these poles so that all parts of the silk thread oryarn will be thoroughly immersed in the bath. When the silk thread oryarn is removed from this bath, it is permitted to dry and, preferably,permitted to dry in the sun.

By following the steps which have been explained above, a resilientthread or yarn is obtained which is curly, kinky and fluffy.

In place of the means mentioned above for.

carbonizing the vegetable matter contained with the silk, the followingmeans may be employed. Liquid muriatic acid is used and aluminum scrapis mixed with the liquid muriatic acid in a dark colored glass vesseland is permitted to remain in the open air in a cool place. The aluminumscrap dissolves and a sediment settles at the bottom of the vessel. Whenthe sediment becomes thick, it is used to carbonize the vegetablematter. Approximately six to eight pounds of this sediment are dissolvedin water at room temperature, one hundred and fifty gallons of waterbeing used to each one hundred pounds of silk and vegetable material,and the said sediment is thoroughly mixed with the water. One pound ofsulphuric acid is then mixed with ten times its volume in water in aseparate vessel and this is mixed with the water in which the sedimenthas been dissolved. The silk and vegetable material is then treated inthis bath by lowering a basket containing the silk and vegetable matterinto the bath and is permitted to remain in the bath for from two tofive hours until the vegetable matter has been eaten away by the bathwithout damage to the silk. The silk may be tested from time to time bytaking a piece of the silk from the bath and heating the same. When thevegetable matter turns brown or black and becomes brittle, all the silkwhich is being treated should be removed from the bath and be heated andthe silk should be shaken to remove the carbonized vegetable matter. Thesilk is then neutralized in another bath in which five pounds of sodaash are dissolved in one hundred gallons of wate'n or two pounds ofliquid ammamas monia are dissolved in one hundred gallons of water. Onehundred pounds. of the silk are then stirred in one of the saidneutralizing baths for approximately fifteen minutes. The silk is thenremoved and drained.

The invention which is the subject matter of this application includesnot only the process which has been described, but also the apparatuswhich has been described and whichis shown in the drawings.

What is claimed is:

l. A method of reclaiming silk thread from a silk fabric including thecarbonization of vegetable matter mixed with the fabric, the treatmentof the fabric with a waxy niaterial to prevent accidental unraveling,the unraveling of the silk thread from the fabric, and the removal ofthe waxy material from the unraveled silk thread.

2. The method of reclaiming silk yarn from old fabric having a certainvegetable contained therein, consisting in first wetting the fabric,then subjecting the wet fabric to a vapor of muriatic acid until thevegetable matter has been v carbonized, heating the fabric until thevegetable matter has become a powder, shaking out the powdered vegetablematter, decoloring and bleaching the silk yarn, washing the silk yarn insoapy water, rinsing the yarn in clear water, spraying the yarn with awaxy substance capable of being melted in hot water, unraveling thefabric and finally subjecting the unraveled fabric to water sufdcientlyhot to remove the waxy substance.

3. The method of recovering silk yarn from fabric containing silkconsisting in wetting the fabric, subjecting the fabric to a carbonizingagent to carbonize the vegetable matter therein, heating the fabricuntil the vegetable matter has become a powder, removing said carbonizedpowdered vegetable matter, spraying the remaining part of the fabricwith parafllne until a suflicient quantity has been added to provide aneasily breakable connection for the respective threads, unraveling thefabric while the fabric is carrying the parafllne, and passing theunraveled yarn in a continuous strand through water sufficiently hot tomelt the paraiiine therein. v

4. The method of reclaiming silk from fabric containing silk, consisting{in subjecting the fabric to a carbonizing agent sufficient to cause allthe vegetable matter to be carbonized, removing said vegetable matter,subjecting the silk to a decoloring and bleaching agent, subjecting thefabric after it leaves the bleaching agent to a soapy solution until thedecoloring and bleaching agents have been removed, rinsing the fabric inclear water, spraying the fabric with parafline powder, removing thepowdered vegetable matter,

spraying the fabric with a waxy substance capable of being melted in hotwater, unraveling the fabric while the waxy substance is thereon, andfinally subjecting the unraveled fabric to water sufllciently hot toremove the waxy substance.

' carbonizing agent until all of the vegetable yarn.

' 6. The method of reclaiming silk yarn from fabric formed of silk yarnand vegetable yarn, consisting in subjecting the entire fabric to a hasbeen carbonized, removing thecarbonized vegetable yarn; applying'a waxysubstance to the remaining yarn, unraveling the remaining yarn while ina waxed condition, and finally subjecting the unraveled waxed yarn toheat until the waxy substance thereon has been removed.

7. The method of reclaiming silk yarn from paraflined yarn to heat untilthe parafline has,

been removed.

ISAAC DAVIS.

